Structural section and structural members composed thereof



June 29,1948. o. CARLSEN STRUCTURAL SECTION AND ST RUCTURAL MEMBERSGOMPOSED THEREOF Flled July 25, 1944 INVEN TOR.

OLAF 0A RLSEN ATTORNEX Patented June 29, 1948 STRUCTURAL SECTION ANDSTRUCTURAL MEMBERS COMPOSED THEREOF Olaf Carlsen, New York, N. Y.Application July .25, 1944, Serial .No. 546,547 6 Claims. (015189-88)The invention relates to structural metal work and more especially to anovel structural section and to structural members such as columns,beams and girders, struts, etc. constructed thereof.

An object of the invention is to provide aimetal section of uniformthickness and strength throughout wherein the moments of inertia about.all principal axes are substantially equal.

Another object of the invention is to provide a section requiringminimum weight of material.

Still another object of the invention is to provide a section which willpossess great strengthand wherein the stresses will be uniformlydistributed.

The invention has for an object, also, to provide a section which willallow of ready access to its different portions in attaching othermembers thereto, as by welding or riveting the same in place.

A further object of the invention is to provide a section whereintwisting forces are counteracted.

A still further object of the invention is toobviate the necessity forbracket plates in making use of a section.

Another object of the invention is to provide a section which will lenditself to the construction of novel structural members.

In carrying out the invention, the novel section is constructed to forma T in cross-section, with top and bottom flanges and in which theformer flange is wider than the latter flange and has its opposite endsturned inwardly at right angles. The depth of the web connecting the topand bottom flanges of the novel section varies directly with the widthof the former flange and by substantially constant increments, which isthe case also of the extent of the inturning of the opposite ends of thesaid top flange.

While the novel section is suitable alone as a structural member,various columns, girders, and other structural members may beconstructed thereof by combining a plurality of the said T- section orby combining with such section or combination of sections otherstructural sections.

The nature of the invention, however, will best be understood whendescribed in connection with the accompanying drawings, in which- Fig. 1is a transverse section through the novel structural section.

Fig. 2 is a view in isometric projection illustrating the use of thenovel section as a column and the manner of applying thereto beams suchas the standard I-beam.

Fig. 3is a similar view illustrating the formation of a column out oftwo of the novel sections, with I-beams attached thereto.

Fig. 4 is a transverse section through a column composed of four of thenovel sections.

Referring to the drawings, the novel section is shown in transversesection in Fig. 1 as comprising an inverted T-shaped member having theweb It] connecting the top flange l l to the base flange l2; and whereused in the specification and claims, T, T-section, T-shaped, capitalletter T are intended to indicate a section comprising a web connectingtop and bottom flanges, the "former flange having its respective endsinturned. The section is made of uniform thickness throughout and, topreserve or balance the moments of inertia about at least three axessuch as the axes l-l, 2-2, and 3-3 of the section, the wider ortopflange H has its opposite ends l3 and I4 turned inwardly to an extentsufiicient to effect the balance.

In the design of a section or the nature set forth, when the width ofthe one flange is made double that of the other, the extentof inturn ofthe wider flange is made to vary directly with the width of the saidtopflange, for example, and by a substantially constant amount or equalincrement. This applies also to the depth of the web ill. As a specificexample, assuming a width of the flange ll of 10 inches and a width,therefore, of the flange" of 5 inches, the web 'con necting theseflanges will then be approximately 7% inches in depth, with the inturnedends of the top flange approximately 3 inches. A section having a topflange width of 20 inches and base flange of 10 inches would require adepth of the web of 13% inches; and in the case of a 30 inch top flange,the web would have to be 19% inches, or a substantially constantincrement of 5% inches in each instance.

The corresponding dimensions for the inturned ends would be, in the caseof the 10 inch top flange, 3% inches; of the 20 inch top flange, 4inches; and in the case of the 30 inch top flange, 4 /8 inches, thusshowing also a substantially constant increment, namely of an inch.

The moments of inertia in all of these examples are figured about threeaxes l-l, 2--2, and 3--3 which pass through'the center of gravity I?) ofthe section; and all are substantially equal for the correspondingsection-in the first instance amounting to inch in the second, to 1015inch; and in the last, to 4300 inch It will be observed that byincreasing the thickness only of larly to a portion of the top flange 24and about 7 the respective inturned ends 25 and 26 of said top flange.The attachment is effected at the web 2'! of a beam, the flanges ofwhich are recessed at the attachment end of the beam to allow ofoverlapping the web 21 on the portion of the top flange 24 of the novelsection.

In Fig. 3, the top flanges 30 and 3| of two like 4 prising four likeintegral members each having substantially the section of the capitalletter T and having substantially equal moments of inertia about morethan two of their respective axes which lie in a common plane and passthrough the center of gravity of a said section, and each member havinga top flange inturned at opposite ends and the said top flanges of therespective members being juxtaposed to form a square in cross-sectionand secured to each other directly along their respective contiguousinturned ends. 5. A column for structural metal work. comprising twolike integral members each having substantially the section of thecapital letter T and having substantially equal moments of inertia aboutmore than two of their respective axes which lie in a common plane andpass through the center of gravity of a said section and each memberhaving a. top flange inturned at opposite sections of the novel designare riveted to each other; and a plurality of I-beams 33, 34, 35, and 36are attached to the corresponding bottom flanges 31 and 38 of the twosections and to the faces 39 and 4B formed by the juxtaposed inturnedends 4| and 42 of the respective top flanges 3B and 3!, said beamsprojecting outwardly therefrom. Due to the increased moment of inertiaresulting from the joining of the top flanges 3i] and 3|, the balance ofthe moments of inertia will be disturbed in the column thus provided.

This is conveniently compensated for or equalized by attaching plates 43and 44 respectively to and along the length of the oppositely disposedfaces 39 and formed by the coacting inturned ends 4| and 42, the size ofwhich plates is to be cal V culated. Y Still another form of structuralmember is illustrated in Fig; 4 in which four like sections 45, 46, 41,and 48 of the novel design are formed into a box like column byjuxtaposing their top flanges to form a square in cross-section, there-'- spective top flanges being attached to one another, for example,by angles 49, 50, 5|, and 52 abutting corresponding inturned ends 53-54,5556, 51'58 and 59-60 of the top flanges. This aifords an exceptionallystrong symmetrical column in which every portion of the material isutilized to full advantage.

I claim:

1. A structural member having substantially the section of the capitalletter T and with sub stantially equal moments of inertia about morethan two axes all lying in a common plane and passing through the centerof gravity of the section.

2. A structural member having substantially the section of the capitalletter T, of uniform thickness throughout, and with substantially equalmoments of inertia about more'than two axes all lying in a common planeand passing through the center of gravity of the section.

3. A structural integral member having substantially the section of thecapital letter T and of uniform thickness throughout, the top flangebeing twice the width of the base flange and its opposite ends inturnedat right angles to said-' top flange and with substantially equalmoments of inertia about more than two axes all lying in a common planeand passing through the center of gravity of the section.

4. A column for structural metal work, com-i ends, the respective topflanges of the two members abutting and being secured to each other, andthe juxtaposed inturned ends providing a pair of oppositely disposedfaces, I-beams secured to said faces to project at right angles to therespective integral members, and I-beams secured to the outer faces ofthe respective base flanges of said integral members to project at rightangles thereto.

6. A column for structural metal work, comprising two like integralmembers each having substantially the section of the capital letter Tand having substantially equal moments of inertia about more than two oftheir respective axes which lie in a common plane and pass through 35the center of gravity of a said section, and each member having a topflange inturned at opposite ends and abutting and'being secured to eachother, and thejuxtaposed inturned ends providing a pair of oppositelydisposed faces, respective plates secured to and along said oppositelydisposed faces provided by the juxtaposed inturned ends, I-beams securedto said plates to project at right angles to therespective integralmembers,

and'I-beams secured to the outer faces of the respective base flanges ofsaid integral members to project at right angles thereto.

I QLAF CARLSEN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS OTHER REFERENCES Pocket Companion-Abridged Ed.1931; Carnegie Steel Co., page 231.

Structural Members & Connections-H001 & Kinne, published by McGraw Hill,N. Y. C., 1923, page 2.

